The invention relates to an adjustable wrench and more particularly to a combined adjustable open-end wrenth and box-end wrench.
The simultaneous manufacture of products having bolts and nuts of metric size and English size has created a need by the amateur and professional mechanic for wrenches of both metric size and English size.
It is known that conventional nonadjustable wrenches including open-end, box-end and combination wrenches having one open end and one box end are commercially available in both English and metric sizes. However, the need for these wrenches in a full range of sizes for both English and metric bolts results in a costly and cumbersome proliferation of wrenches.
It is also known to provide an adjustable wrench for fitting a full range of bolts of metric and English sizes. The best known commercially available adjustable wrench is the so-called "crescent" wrench which has an open end between a fixed jaw and another jaw which is adjustable by a rotatable screw. A disadvantage of the crescent wrench is that several revolutions of the screw is required to change the wrench between the largest and smallest sizes. Another disadvantage is that the crescent wrench is difficult to maintain at a selected adjusted position because a very slight inadvertent rotation of the screw enlarges the opening sufficiently to result in rounding of the corners of the bolt head. Furthermore, the adjusting screw is oriented generally normal to the longitudinal axis of the wrench handle, thereby causing the crescent wrench to have a large width adjacent the jaws which may not conveniently fit a bolt head because of obstructions located adjacent the bolt head.